Résumé
In order to develop management strategies in an intensive agricultural region of south-western France, we examined in a two-year experiment, the consequences of change in emergence date on the growth and development of the clonal perennial Cyperus esculentus. Germinated tubers emerged in early May, June and late July and were harvested 4, 5 or 6 months after emergence. Total shoot and tuber number per individual increased throughout the growing season, then significantly decreased in autumn. All plants produced tubers, the primary means of reproduction, including the smallest and latest emerging cohorts, but the allocation to tubers decreased with emergence date. However, emergence date had no effect on the emergence rate of the shoots, indicating that the reduction in total shoot production was not counterbalanced by an acceleration of this production when the growing season shortened. Consequently, management programs should advantageously integrate agricultural practices (i) that avoid periods without crops between April and October, (ii) that delay C. esculentus emergence and (iii) that include interventions on the newly emerged individuals.